---
title: "Onyx: FreeSewing's Onyx One-piece"
sidebar_label: Onyx One-piece
---
<DesignInfo design="onyx" />
## Designer Notes {#notes}
Onyx is my second design. Like Shelly, the design was made to address a need
for sensory compression garments (related to autism), as well as the difficulty
in finding sleeved and legged gender-neutral one-piece swimsuits sized for
adults.
What started as a swimsuit/unisuit design turned into a more general design
capable of making other forms of casual or athletic one-piece outfits. I've
made one-piece pajamas with the Onyx design, and the design should be capable
of making simple rompers (such as pajamas rompers), leotards, and unitards, as
these garments all share the same general form, varying in fabric, ease, and
sleeve/leg length more than in their core design. Options for ribbed cuffs were
added to aid in making pajamas with the design, and pajamas were also a major
reason for the addition of the optional hood (sun protection is the other
reason).
The skirt was added in for modesty, primarily for the swimwear, though it does
allow the Onyx design to be used to make gathered dresses with built-in shorts.
Onyx does copy a number of Shelly's features, including raglan sleeves for
mobility and the use of symmetrical front and back parts, except for the neck
and head.
Onyx is named after the gemstone and its deep black color, which not
coincidentally is a great base color for Onyx swimsuits, particularly if one
wants them to look like a wetsuit.
A bit of history: Onyx may never have been born had it not been for the
anti-LGBTQ+ protests and boycotts in the spring of 2023, which led to a unisuit
that I particularly liked being pulled from the shelves of a major US retailer,
and me needing a suitable replacement.
Thrunic
## What You Need {#needs}
To make Onyx, you will need the following:
- Basic sewing supplies
- (Recommended) A serger/overlock machine. Light, strong, and stretchy seams
are important for this garment.
- Between 1 - 5 meters (1.1 - 5.5 yards) of a suitable fabric, depending on
size and style ([see Fabric options](#fabric))
- Long sleeves, long legs, use of lining, larger measurements, more ease, use
of a hood, and use of a skirt will all increase fabric requirements.
- A typical adult unisuit with short sleeves and short legs with a self-lined
body will take about 2 meters of fabric.
- (Optional) Rib knit fabric for the neck, arms, and legs, if desired.
## Fabric Options {#fabric}
This pattern is designed to work with stretch/knit fabrics, such as swim
fabric, fleece, and jersey.
For unisuits, unitards, and other performance-oriented and form-fitting
garments, four-way stretch fabric such a 20% spandex blend is strongly
recommended. For more casual garments, such as one-piece fleece pajamas,
kigurumi, rompers, and jumpsuits, most knit fabrics can be used. Fleece can be
used to make warm winter pajamas, while jersey knit can be used to make a
summer romper.
The raglan sleeves lend themselves well to using different colors/prints for
the body and for the sleeves. Contrasting fabrics can also be used on the skirt
or hood.
Lined portions of the garment lend themselves well to embroidery, as the
stabilizer (strongly recommended) and stitching will be kept away from the
wearer's body by the lining. The chest, next to the zipper, is a particularly
good spot, both because it's prominent, and because the chest doesn't stretch
vertically much, since it's near the zipper.
With swim fabric/spandex, it is recommended to make the neckband out of the
same material used for the body. For less stretchy fabric, such as cotton
jersey knit, ribbing is recommended.
## Cutting Instructions {#cutting}
- Cut **1 front** part _on the fold_ -or- cut **2 front parts** (refer to
pattern piece)
- Cut **1 back** part _on the fold_ -or- cut **2 back parts** (refer to pattern
piece)
- Cut **2 sleeve** parts
- Cut **1 crotch gusset** part _on the fold_
- Cut **1 zipper guard** part _on the fold_ (optional)
- Cut **1 neckband** part _on the fold_ (optional)
- Cut **2 hood** parts (optional)
- Cut **1 hood front** part _on the fold_ (optional)
- Cut **1 skirt** part _on the fold_ (optional)